Clamp



M. KIEFER May 25 1926.

CLAMP Filed April 24, 1924 mkzal 1/ Patented May 25, 1926.

. UNITED, STATE I MICHAEL KIEIEE-R, ore/roman, GERMANY.

CLAMP; 4

Application filed April 24, 1924, Serial No. 708,818, and in Germany May 2, 1 923.

This invention relates to an improved clamp and particularly 'to a so-called edgeclamp, that is to say, a tool for clamping a piece of work from three sides including an edge face thereof.

With this object in view the improved clamp comprises two lateral jaws acting in opposition to clamp the work therebetween, and a third jaw adapted to act in a direction perpendicular to that of the first stated two aws, in order to exert an end pressure on the edge face ofthe work gripped and clamped by the two first stated jaws.

I am aware that clamps of the kind old but the hitherto suggested clamps are objectionable for the reason that only the two lateral jaws are adapted to swing in and out whilst the third or intermediate jaw' is stationary in this respect. This disadvantage results in that a reliable clamping eflect cannot be obtained at many a kind of work and the tool, in such a case, tends to slide off when overstrained to ensure a firm ri 6 J5 further disadvantage of the clamps of the kind hitherto employed resides in the fact that two or more connecting joint bridges between the swinging aws are indispensable, said bridges acting to impair the required rigidity of the clamp so that the latter will get bent at any excessive clamping pressure. Moreover, the said joints or links involve inaccuracies in the adjustment and fixation and the handling of the tool is very troublesome.

My improved clamp remedies all of the said defects by the provision of jaws which, inclusive of the intermediate or third jaw, are adapted to swing or oscillate laterally, and further by the provision of a supplemental screw for the actuation of the two lateral jaws mounted on a common pivot to turn thereabout.

In the accompanying drawing forming a part of this specifications. preferred form and manner in which the invention maybe embodied and practised is shown by way of example.

In the drawing the two lateral swinging arms or jaws are each constituted by two superposed angular members made of sheet steel and firmly united 'by means of bolts (1. The one arm or is shaped to form a double bell-crank lever 0, (Z and adapted to turn about a pivot 6, while the other-arm or jaw. c is shaped to form a belleranlz; lever likewise .mou-nted to turn about said pivot Z) and provided with a rug). In the end of the arm (Z a square block 9 is pivotally inserted between the two members constituting thej aw and a threaded spindle or screw 72. is pivotally connected with the said block a. Firmly connected or integral with the lug f is a nut 2' in which the screw 72 engages.

The common pivot Z) of the two jaws a, (Z and e is not stationary but mounted to turn freely. The middle portion thereof located intermediate the members forming the aws is enlarged to form a collar is having a threadedv opening for the reception of the spindle or screw Z of the third jaw m which is attached to the lower end of the screw Z in a known manner by means of a ball and socket joint, as will be readily understood from the drawing.

In operation the two lateral jaws 0, d and are manually actuated 'by means of the spindle h to grip the work a and to hold it firmly between them, thus bringing the two aws from the open position shown in full lines to the clamping or closed position illustrated in dotted lines. If required, the intermediate jaw m may also be turned about its pivot and placed in front of the edge face of the work in order to engage the same upon manually turning the spindle Z. Thus the jaws of the clamp are adapted to be separately applied to the work which, as far as my knowledge goes, is not possible in any ofthe hitherto known clamps.

As my improved clamp is of a very strong and durable construction a very high degree of compression can be obtained so that for this reason and owing to the separate adjustment and handling of the jaws the latter can be accuratelyapplied to the work and are prevented from sliding off. \Vhile I have shown my invention embodied in a certain construction, it is not to be inferred that such construction represents the only form in which my invention may be embodied, but is illustrated and described only as illustrative of a form now preferred by me and to make clear the principle and the manner of the application of my invention. I do not of course desire to be limited to the exact details of construction and arrangement shown and described as modifications are no doubt possible which will come within the scope of the invention. "What I claim isi j I j v i. A clamp of. the kind described, com

prising in combination a pair of jaws pivoted on the same axis to swing towards and from each other, a third jaw also pivoted on said axis and extending between said pair, and means for swinging said third jaw and adjusting it radially with respect to said axis.

2. A clamp of the kind described, comprising in combination a pair of jaws 10 pivoted on the same axis, a block also pivoted on said axis having a threaded aperture extending substantially at a right angle to said axis, a threaded stem in said aperture, a clamping jaw carried by one end of said stem and a handle secured to the other end of said stem.

In testimony whereof I have hereunto affixed my signature.

MICHAEL KIEFER. 

